Mirrorless camera systems finally feel like they have come of age. Yes they've been knocking around for a couple of years, but over the last 12 months we've seen models which can genuinely rival DSLRs in terms of image quality and performance. While this choice is great for the camera-buying public, it also makes it even more tricky when deciding which system to invest in ... which is why we decided to compile a guide to the top mirrorless camera releases of 2012.